The present invention relates to modular coil cores for an electric motor for use with the disc-driving system which drives hard discs and floppy discs used as an external memory device of an information system.
Recently, the overall dimensions of data memory system such as hard discs and floppy discs have to become smaller and thinner in conjunction with the achievement of power economy. Reflecting this trend, manufacturers of those motors for driving these data memory systems study the improvement of the structure, performance, and the processing system today.
Referring now to the accompanying drawings, an example of a conventional motor is explained below.
FIG. 3 is the sectional view of a conventional motor. The conventional motor shown in FIG. 3 is typically composed of a rotor unit having stationary rotor yoke 4 whose inner circumference is provided with a ring-shaped multipole rotor magnet 3 which is secured via hub 10 to the rotary shaft 2 rotatably being supported by pair of bearings 1, a multi-layer stator yoke 7 which is set into the lateral surface of a housing 6 containing the pair of bearings 1, and a stator unit having coil 8 which is wound on the stator yoke 7. The printed substrate 9 on the base 5 securing the housing 6 disposes circuits elements such as hall elements needed for driving the motor unit.
FIG. 4 is the plan view of the stator yoke shown in FIG. 3. Each stator yoke 7 shown in FIG. 4 has the poles wound with coiled wires as shown in FIG. 5.
Nevertheless, since the stator yoke 7 has a complicated shape in the above noted conventional structure, it is extremely difficult for the assembly system to properly wind coiling wire on each poles. Furthermore, it is quite necessary for the assembly system to simplify the method and process for winding coiling wires on the poles in the light of the operating requirements.